It is a fact of life that the shoes of an individual will eventually become old and wear out. For those who are not avid runners, the terms ‘get old’ and ‘wear out’ are often associated with the appearance of a particular pair of shoes. However, for the avid runner, this is not always the case. Many running injuries are caused by the continued use of improper or worn running shoes. An increase in the number of incidences of injury can be directly correlated to the degradation of the materials within the sole of a running shoe. Unfortunately, shoes that have been worn past their useful life do not always appear worn, especially if those shoes are only used for running. In fact, it is nearly impossible to tell if a shoe has been worn beyond its useful life based on appearance alone.
As is known, the average running shoe lasts between 300 and 500 miles before the soles of the shoes begin to degrade. This threshold is dependant on several factors such as the size of the person wearing them or the wearer's running style. As heretofore described, when the sole of the shoe begins to degrade, the risk for injury to the runner can increase significantly. Nevertheless, there is no mechanism for advising a runner that a shoe is worn out. Presently, the runner has two options for determining if a pair of shoes has worn out. The first option is to keep a log of the miles run in a pair of shoes and to know how many miles a pair of shoes typically lasts from past experience. The second option a runner uses to determine if a pair of shoes has worn out is the feel of the shoes. Avid runners can sometimes determine that a pair of shoes is becoming worn by feeling extra soreness in their muscles or joints after a run. It can be appreciated that there are flaws in both of these prior methods. Therefore, it is highly desirable to provide a device that can measure the wear of a shoe sole in a quantitative manner and alert a runner when a new pair of shoes is needed.
Therefore, it is a primary object and feature of the present invention to provide a device and method for measuring the wear of a sole of a shoe in a quantitative manner and for alerting a runner when a new pair of shoes is needed.
It is a further object and feature of the present invention to provide a device for measuring the wear of a sole of a shoe that may be easily incorporated into a standard running shoe.
It is a still further object and feature of the present invention to provide a device and a method for measuring the wear of a sole of a shoe that are inexpensive and simple to utilize.
In accordance with the present invention, a device is provided for determining the wear of a sole of a shoe. The device includes a first sensor that is receivable in the sole of the shoe. The first sensor generates a first signal in response to a first impact force thereon. A second sensor is also receivable in the sole of the shoe. The second sensor generates a second signal in response to a second impact force thereon. A control circuit is connectable to the first and second sensors. The control circuit generates an alert signal in response to the first and second signals.
It is contemplated for the first and second sensors to be pressure sensors and for the control circuit to include a first amplifier for amplifying the first signal and a second amplifier for amplifying the second signal. The control circuit also includes a differential amplifier for determining a difference between the first amplified signal and the second amplified signal and for amplifying the difference between the first amplified signal and the second amplified signal. In addition, the control circuit includes a comparator for comparing the amplified difference between the first amplified signal and the second amplified signal with a threshold and for generating an illumination signal if the amplified difference between the first amplified signal and the second amplified signal meets the threshold. A light emitting diode generates the alert signal in response to the illumination signal.
In accordance with a further aspect of the present invention, a device is provided for determining the wear of a sole of a shoe. The device includes a first pressure sensor receivable in the sole of the shoe. The first sensor generates a first signal that is proportional to a first impact force acting thereon. A second pressure sensor is also receivable in the sole of the shoe at a location axially spaced from the first pressure sensor. The second sensor generates a second signal that is proportional to a second impact force acting thereon. A control circuit is connectable to the first and second pressure sensors. The control circuit compares the difference between the first and second signals to a threshold and generates an alert signal in response to the difference between the first and second signal meeting the threshold.
It is contemplated for the control circuit to include a first amplifier for amplifying the first signal and a second amplifier for amplifying the second signal. The control circuit also includes a differential amplifier for determining a difference between the first amplified signal and the second amplified signal and for amplifying the difference between the first amplified signal and the second amplified signal. In addition, the control circuit includes a comparator for comparing the amplified difference between the first amplified signal and the second amplified signal with a threshold and for generating an illumination signal if the amplified difference between the first amplified signal and the second amplified signal meets the threshold. A light emitting diode generates the alert signal in response to the illumination signal.
In accordance with a still further aspect of the present invention, a method is provided for measuring the wear of a sole of a shoe. The method includes the steps measuring an impact force exerted on a first portion of the shoe and measuring an impact force exerted on a second portion of the shoe. The impact force exerted on the first portion of the shoe is compared with the impact force exerted on the second portion of the shoe. Thereafter, an alert signal is generated if the difference between the impact force exerted on the first portion of the shoe and the impact force exerted on the second portion of the shoe meets a threshold. A light emitting diode is illuminated in response to the alert signal.
The sole of the shoe includes a midsole affixed to an upper surface of an outsole. The method of the present invention may include the additional steps of positioning a first sensor between the outsole and the midsole to measure the impact force exerted on the first portion of the shoe and positioning a second sensor on an upper surface of the midsole to measure the impact force exerted on the second portion of the shoe. The first sensor and the second sensor are axially aligned.
The step of comparing the impact force exerted on the first portion of the shoe and the impact force exerted on the second portion of the shoe may include the additional steps of generating a first signal that is proportional to a first impact force and generating a second signal that is proportional to a second impact force acting thereon. Thereafter, the first and second signals are amplified. The difference between the first amplified signal and the second amplified signal is determined.
A control circuit is provided to compare the impact force exerted on the first portion of the shoe and the impact force exerted on the second portion of the shoe and to generate the alert signal. The control circuit is enclosed in a capsule which may be interconnected to the shoe.